1. Field of the Invention
The present invention relates to novel intermediates for producing oxazolidinedione derivatives of a formula (13): ##STR2## where X represents a halogen atom; R.sup.2 represents a cycloalkyl group having from 3 to 8 carbon atoms, or an alkynyl group having from 3 to 5 carbon atoms, the cycloalkyl group being either substituted or unsubstituted; and Z represents a methyl group, or an ethyl group; the derivatives being used as an active ingredient for herbicides; as well as to methods of preparing them.
More precisely, the present invention relates to diphenylcarbonate derivatives of a formula (11): ##STR3## where X represents a halogen atom; R.sup.3 represents a nitro group, an amino group, an isocyanato group, or R.sup.1 OCONH; and R.sup.1 in R.sup.1 OCONH represents an alkyl group having from 1 to 8 carbon atoms, or a phenyl group, the alkyl group being either substituted or unsubstituted; and phenylcarbamate derivatives of a formula (12): ##STR4## where X represents a halogen atom; R.sup.1 ' represents an alkyl group having from 1 to 8 carbon atoms, a phenyl group, or a benzyl group; R.sup.4 represents a hydrogen atom, a cycloalkyl group having from 3 to 8 carbon atoms, or an alkynyl group having from 3 to 5 carbon atoms, the cycloalkyl group being either substituted or unsubstituted; as well as to methods of preparing them.
2. Prior Art Oxazolidinedione derivatives of formula (13) are compounds having an extremely excellent herbicidal activity. (Refer to Japanese Patent Application Laid-Open Nos. 62-167713 and 2-25405.) As methods of preparing them, those described in Japanese Patent Application Laid-Open Nos. 62-174065 and 3-178957 are known. However, the known methods are not always satisfactory in point of the purity and yield of the products. No method of simply preparing oxazolidinedione derivatives via diphenylcarbonate derivatives or phenylcarbamate derivatives has ever been developed.